What's the Best Mega Man Game for Someone Who's Never Played the Series?
The Mega Man franchise has classic 2D platformers, the Zero/ZX action series, the Battle Network RPGs, and more recent entries, so picking a starting point matters.
I think, The strongest recommendation for pure newcomers is Mega Man 11.
It features modern visuals, excellent controls, a helpful difficulty selection (including a very approachable "Newcomer" mode), and the classic robot-master structure that defines the series — without the extreme difficulty spikes of the older games. It also has a great soundtrack and polished level design that feels fair.
If you prefer the original 8-bit/16-bit feel, Mega Man 2 is the classic "best starting point" among the old games. After either of those, jump into the Mega Man Zero series (especially Zero 2 or the Zero/ZX Legacy Collection) if you want faster, more stylish action. Avoid starting with the early NES games or the 3D Mega Man Legends titles until you already like the core formula.